Fluid amplified liquid spring shocks and/or shock absorbers

ABSTRACT

A shock absorber which uses fluid amplification to provide programmed fluid flow and highly efficient shock curves without the necessity of expensive and inefficient metering holes, metering pins, and/or pressure responsive valves is provided by the interaction of: (1) a fluid passage clearance between a shock piston head or vane and the chamber, which houses and is swept by the head or vane, (2) an indentation formed around the periphery of the head or vane, and (3) a plurality of openings between the head or vane and the indentation formed around the periphery of the head or vane.

United States Patent Taylor Oct. 17, 1972 [54] FLUID AMPLIFIED LIQUIDSPRING SHOCKS AND/OR SHOCK ABSORBERS [72] Inventor: Paul H. Taylor, 3877East River Road, Grand Island, NY. 14072 [22] Filed: Oct. 30, 1970 [211App]. No.: 85,795

Related US. Application Data [62] Division of Ser. No. 764,377, Sept.30, 1968,

abandoned.

[52] US. Cl ..188/306 [51] Int. Cl ..Fl6d 57/02 [58] Field of Search..188/306, 307, 308, 309, 310; 16/58 [56] References Cited UNITED STATESPATENTS 1,813,666 7/1931 Elliott ..188/309 1,970,369 8/1934 Focht..188/306 2,027,423 1/1936 Gardiner ..188/308 X 3,361,231 l/l968 Carroll..188/306 X FOREIGN PATENTS OR APPLICATIONS I 597,481 8/1925 France..188/306 693,875 9/1930 France ..188/306 Primary Examiner-George E. A.l-lalvosa Attorney-Hume, Clement, l-lume & Lee, Ltd.

[57] ABSTRACT A shock absorber which uses fluid amplification to provideprogrammed fluid flow and highly efficient shock curves without thenecessity of expensive and inefficientmetering holes, metering pins,and/or pressure responsive valves is provided by the interaction of: (1)a fluid passage clearance between a shock piston head or vane and thechamber, which houses and is swept by the head or vane, (2) anindentation formed around the periphery of the head or vane, and (3) aplurality of openings between the head or vane and the indentationformed around the periphery of the head or vane.

6 Claims, 15 Drawing Figures PATEN FEDHBI 1 1 m2 SHEET 3 [IF 5 FLUIDAMPLIFIED LIQUID SPRING SHOCKS AND/OR SHOCK ABSORBERS CROSS-REFERENCE TORELATED APPLICATIONS This application is a division of my earlierapplication, Ser. No. 764,377, filed Sept. 30, 1968, which is nowabandoned.

BACKGROUND OF THE INVENTION This invention generally relates to shockabsorbers which accomplish variations in shock mitigation through fluidamplification without the use of costly, and often inefficient,assemblies such as metering pins, metering holes, metering grooves,metering systems, or pressure responsive valves.

Although there are a number of conventional shock absorbers which usefluids as a dampening medium for shock absorption, such shock absorberssuffer from an array of deficiencies. One such shock absorber, forexample, employs a rod, a dashpot head associated with the rod, and achamber which houses therod and head and which is traversed by themovement of the head and rod. Such absorbers also typically have anorifice or plurality of orifices communicating with each side of thechamber to permit fluid flow through the orifices and between points inthe chamber which areseparated by the dashpot head. As the dashpot headsweeps the chamber, energy is absorbed.

Another type of shock absorber employs an inner shock tube which ishoused within a larger diameter cylinder. The inner shock tube houses adashpot head while the space between the inner tube and outer cylinderforms an external gas reservoir to accomodate piston rod displacement.Typically, the inner tube has a series of metering holes of the same ordiminishing size, radially spaced along the length of the inner tube orconversely a series of the same size holes spaced progressively atincreased distances along the inner tube. Theeffect of the meteringholes in each instance, however, is to cut off the flow of fluid indirect proportion to the diminishing velocity of the dashpot head.

Yet another type of shock absorber employs precisely tapered meteringpins to provide gradual diminishing fluid flow in the shock absorber.Such shock absorbers, for example, typically utilize metering pins whichpierce a metering hole and which co-act with the hole when submersed influid.

Finally, other types of shock absorbers employ a plurality ,of pressureresponsive valves instead of either metering holes or metering pins inan effort to accomplish uniform predetermined fluid flow and shockresistance in shock absorbers. Typically, such pressure responsivevalves open at fixed pressures to provide uniform predetermined shockresistance or a square energy card. The most common type of shockabsorber which uses pressure responsive valves is the telescopingautomobile shock absorber or older vane-type shock absorbers. Generally,in these shock absorbers, one pressure responsive valve is set to openupon compression of the piston rod and head and another valve is set toopen to a control position upon rebound. Typically, plate type valves,similar to a Belleville spring washer, are used in such absorbersalthough it is known that balls with coil springs can also be used as asuitable pressure responsive valve.

In any case, each of the conventional shock absorbers referred to abovesuffer from a number of deficiencies. For example, the shock absorberswhich use a plurality of orifices to communicate between opposite sidesof the swept chamber have been observed to produce inefficient shockcurves when compared with absorbers producing square wave curves.Similarly, shock absorbers using an inner tube,,an outer cylinder, andmetering holes have been observed to produce square top waves at onespecific design velocity, but, in some cases, produce peaks as thedashpot head passes the metering holes. In effect, therefore, a seriesof steptype shock curves are produced. In addition, the use of extratubes and metering holes has proved costly and inefficient. Shockabsorbers having metering pins have alsov proved costly, and in manycases, inefficient. Metering pins, for example, have often goneeccentric, causing erratic metering and fluid flow in the shockabsorber. Finally, shock absorbers employing pressure responsive valveshave experienceddifficultieswhen the cracking or opening pressure forthe valves exceeds the operating resistance for the absorber as, forexample, when the ball or plate valve exposes more area after theorifice is open, thereby requiring less fluid pressure to hold the valveopen.

SUMMARY OF THE INVENTION In accordance with this invention, a new andimproved shock absorber is provided by utilizing a piston head or vanecharacterized by having a fluid passage clearance between the pistonhead or vane and the chamber which houses and is swept by the head orvane, an indentation formed around the peripheral surface of the head or'vane adjacent the walls of the chamber, and a plurality of orifices oropenings formed between and interconnecting the transverse surface ofthe head or vane and the indentation in the peripheral surface of thehead or vane, so that the high velocity fluid flow through the fluidpassage clearance entrains fluid flowing through the openings whichinterconnect the transverse surface of the head or vane and theindentation formed in the peripheral surface of the head or vane.

Accordingly, the principal object of this invention is to replacepressure responsive valves in a shock absorber with simple orificeswhose flow is subject to amplification from metered flow of anotherorifice when pressure differentials occur in said shock absorber.

A second principal object of this invention is to eliminate taperedmetering pins.

A third principal object of this invention is to provide a diminishingflow without an internal perforated orifice tube.

A fourth principal object of this invention is to eliminate diminishingorifices in a shock absorber.

A fifth principal object of this invention is to provide a simple shockabsorber which provides essentially uniform force resistance within alarge range of velocities.

A sixth principal object of this invention is to provide a complex shockabsorber response with a few working parts.

Another .related object of this invention is to eliminate the peaks inshock force associated with pressure responsive valves or fixedorifices.

Another related object of this invention is to provide a shock absorbersystem which is capable of functioning in a simple high pressure liquidspring or hydrapneumatic spring.

Another related object of this invention is to provide a shock absorberwhich can be-reduced in size.

Still a further object of this invention is to provide a simple shockabsorber which can duplicate the ride'resistance of an automobile shockabsorber through all velocities.

Still another object of this invention is to reduce shock pressures fora given force.

Still another object of this invention is to provide a shock absorberwhich can be miniaturized.

Still another object of this invention is to provide shock absorptionfrom all fluids, both liquid and gases.

, Yet another object of this invention is to provide a shock absorberwhich relieves overloads without destroying itself.

Still a further object of this invention is to provide a shock absorberwhich has no adverse temperature problems.

'Another principal object of this invention is to provide a shockabsorber which can be mass produced from other hydraulic apparatus toachieve low-cost manufacturing.

Another principal cost object of this invention is to provide for a widerange of shock absorber functions with a common range of sizes and partseasily adapted for all shock purposes by simple low-cost procedures.

A related principal cost object is to provide a shock absorber for massproduction uses.

An important cost object of this invention is to provide a low-costshock absorber principle which, when combined with low-cost liquidsprings construction, makes liquid springs competitive in massproduction markets.

Still another principal cost object of this invention is to provide ashock absorber which is readily fabricated by semi-skilled help.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be more readilyunderstood by reference to the following drawings in which:

FIG. 1 is a longitudinal sectional view of a liquid spring shock withsimple orifices arranged according to the principles of this invention.

FIG. 1A is a graph illustrating the essentially square energy waveactually delivered from such a shock absorber.

FIG. 2 is a fragmentary partial view of the fluid amplified orificessection of this device employing the principles of fluidics andillustrating the relative orifices shape, dimensions, and clearances toachieve this unusual effect.

FIG. 3 is an identical view to FIG. 2 but illustrating the flow oncompression of said liquid spring shock and the way in which that flowis amplified through the orifices.

FIG. 4 is a view similar to FIGS. 2 and 3 illustrating how this flow isnot amplified when the device is extending or on rebound.

FIG. 5 is a longitudinal section view of a conventional automobile shockabsorber without support spring forces and employing the principles ofamplified flow in the shock absorber and an impact spring.

FIG.- 5A illustrates an alternate dashpot head with a check valve toachieve differentials in amplified flow between compression andextension.

FIG. 6 is a graph showing how this device works from a position of rest,such as support height of a vehicle functioning as a liquid spring onimpact.

FIG. 7 is a graph illustrating the high speed return of a wheelcontrolled with this shock absorber due-to its impact spring.

FIG. 8 is a longitudinal view of a tubular liquid spring orhydrapheumatic spring shock employing this fluid amplified flow incooperation with an area reducing structural stud and a common orifice.

FIG. 9 is a section of a similar device collapsed, but using a stepmetering pin for a plurality of differential square topped energy waves.

FIG. 10 is a view of a hydraulic cylinder made from the same componentof the device of FIG. 1.

FIG. 1 l is of a hydraulic or pneumatic cylinder which employs fluiddampening according to the teaching of this invention.

FIG. 12 is a similar view of a vane-type shock absorber employing thisnovel form of amplified flow dampening.

FIG. 13 is a sectional view taken as noted of the device of FIG. 12.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 illustrates the simplestform of Liquid Spring shock absorber 20 having one moving part, pistonassembly 30, which performs the function of five pressure responsivevalves to relieve 20,000 p.s.i. liquid, providing you could buildpressure responsive valves for 20,000 p.s.i. Piston assembly 30 cylinder21 and cap 25 with seal 26 and 26a being the bare minimum of partsnormally associated with the simplest of fluid devices, a pneumatic orhydraulic cylinder or liquid spring shock. Please note that in ahydraulic cylinder, groove 32 would be a normal 0 ring groove, thisliquid spring shock device with ports at 21a and an additional port 126in cap 25, as shown in FIG. 11, is a hydraulic cylinder and it isintended that these common parts provide both liquid spring, liquidspring shock, hydrapneumatic shock or shock absorber, pneumatic andhydraulic cylinder thus effecting manufacturing economies permitting allthese fluid products to be sold cheaper with resulting larger marketsfor each class of device.

The liquid spring shock 20, as is illustrated in FIGS. 1, 2, 3, and 4,being particularly designed for cushioning freight cars, has, forexample, an CD. of 12 inches, length of 24 V4 in. and a stroke of 6 in.and providing 50,000 ft. lbs. of energy in a 24 draft pocket of astandard freight car compared with 70,000 ft. lbs. in the standardfriction draft gear it replaces. Amazingly, while other hydraulicrailroad cushioners have been designed for this service, providing150,000 ft. lbs. of energy absorption, they are conventional with aninner perforated shock tube providing internal pressures double thisLiquid Spring Shock which is normally considered a high pressure device.This pressure advantage of fluid amplified dampening attests to thevalue of this invention in hydraulic shock applications. Using fluidamplified dampening one can provide more energy absorption in a givensize, or lower pressures or reduced size of the shock absorber.

In the construction shown in FIG. 1, piston rod 30a is, for example,made of high strength rnaraging 350,000 psi. yield Nickle Alloy Steelmaterial which is finished soft, assembled by riveting to previouslyhardened but not drawn piston head 31 of S.A.E. 4340 material. Theentire piston assembly 30 is then heat treated at 900 F. which draws thepiston head 31 to make it tough and simultaneously heat treats themaraging steel piston rod 300 to 350,000 p.s.i. yield. The entireassembly is then strong and tough with a small diameter liquid springpiston so internal pressures can be low for the spring function to matchthe low pressures for the shock force, permissible with this invention.

We will now discuss in detail how this low pressure shock absorberoperates. The annular collector ring 32 (preferably identical to an 0ring groove) has a plurality of connecting drilled passages 33 incommunication therewith. Ideally, piston head 31 has a slightly taperedor curved venturi like surface 31a, shown best in FIGS. 2, 3, and 4, onits exterior, although it can be flat or concave and work, although notas efficient flow-wise. Referring now to FIG. 2, this tapered surfaceprovides a minimum clearance C and a maximum clearance C to cylinderinner wall surface 23 as shown in enlarged detail in FIG. 2. Thisclearance (of any type), groove 32 and communication system 33 in anyshape or combination when used with a moving piston, forms the essentialingredients of this fluid amplified flow invention for a shock absorber.The various types of amplified flow through in and around this labyrinthproviding the equivalent of a metering pin, pressure responsive valve,metering tube, metering holes or any system for diminishing flow toprovide uniform shock resistance (square card) in a shock absorbersystem. This is accomplished without reduction in piston area formetering-pins, tubes, or pressure responsive valves with resulting lowerpressures.

Referring now to FIG. 3, it illustrates the manner in which fluidamplification, in accordance with velocity, takes place. The directionof the piston is in compression as shown in direction 38. Through theclearance CC, a flow F is energized because of the difference P, (highpressure) and P or low pressure on either side of dashpot head 31. Thispressure difference, if it is high, provides high flow through clearanceCC,. If it is low, it provides low flow through clearance CC Normally,with a clearance of this type, there is a predetermined maximum flowpoint at which it can pass enough liquid, before the pressure peaks outon impact since the impact velocity is high initially. A normal orificeflow of this type through this annular or a hole orifice causes a veryhigh peak with a declining pressure wave thereafter going to zero as thepiston is decellerated to zero velocity. This is classic force responsein any orifice shock absorber. It normally provides a 60 percent energycurve in which the area under the force line equals 60 percent of thearea generated if the peak shock force was maintained over the entirestroke. To absorb a given energy with a known peak shock force,preferably twice the stroke must be provided to absorb this givenenergy. This doubles the shock absorber costs. Often the mechanism willnot absorb this initial high G loading.

However, in this invention, as shown in FIG. 3, flow F passing groove 32entrains with its flow F from orifices 33 in proportion to its velocityby C. The exhaust fluid, therefore, FAF is an amplified flow A of FAF,in direct proportion to the velocity which therefore provides theconstant force graph FIG. 1A or a 95 percent efficient shock curve. Thisefficiency is never approached with conventional shock absorbers havingjust orifice flow and is difficult with a tapered metering pin ormetering tube.

In the railroad design of FIG. 1, for example, this would call for areduction in piston size (raising pressures for a given shock force) topermit the introduction of a metering tube, the actual first design ofthis unit. This, in turn, provided pressures 30 percent higher with thesmaller area of the original unit. In my design illustrated in FIG. 1,I, therefore, have a 95 percent efficient shock curve with a large lowpressure dashpot, small piston rod for low liquid spring forces, and anefficient square energy curve without metering apparatus. Referring nowto FIG. 4, the flow effect of an extension 39'after impact can beobserved. Since in most like compressions for this rail shock one wishesto just initially accelerate the coupling to extend rapidly from zeroreversal velocity and, thereafter, slow it down, a flow R between P P,is initiated which is preferably not amplified in accordance with thisinvention. Therefore, the velocity of piston 30 is initially smoothlyaccelerated, then is progressively diminishing on extension, inaccordance with a low spring force and high flow resistance.

In FIG. 1, I illustrate heavy walls 21 on cylinder 20 which deflectslightly, thus enhancing flow by clearance C. By suitably changing thethickness of wall 21 to yield more, a pressure relief amplification canbe obtained so that there is no flow limitation on this device. Allpressure responsive valves have flow limitations after which the valveis damaged or the unit overloaded. This device tends to relieve its ownoverloads by its amplified flow and its wall deflection when it isproperly designed.

FIG. 1A illustrates typical force stroke relationships for rail use ofthis novel liquid spring 20. As shown at 6 miles per hour, peak shockforce of 220,000 pounds are provided with an initial low rate of G slopeinitially (force due to acceleration). At l 1 miles per hour the curveis a very efficient 90 percent energy curve providing maximum absorptionin a 6-inch stroke cushioning device of 250,000 foot pounds over 6.4inches of stroke. This is accomplished with internal pressures 40percent less than existing coil spring return railroad cushioners.

Referring now to FIG. 5, it shows a vehicle shock absorber suspension40, normally used with a mechanical spring, having a cylinder 50 and apiston assembly 60. Cylinder assembly 50 has an inner shock tube 51containing the high pressure on shock mitigation and bottoming intrepanned seal groove 71 on a seal 70. Elastomeric seal 72 seals againstthe bore 52 of cylinder 50 and end cap 53 has a guide ring 54 thereinfor preventing the extrusion of seal 70. Cylinder 50 is crimped at 50a.

In accordance with my suspension teachings, piston rod A has a washer 62thereon and elastomeric cushion 61 for taking impacts therewith. Pistonhead 63 has a collector ring 64 and a plurality of passages 65 which,with clearance 66 to the bore 55 of tube 51, provides the amplifiedorifice flow previously discussed. A plastic resilient end member 56nests in the end 57 of the cylinder 50 to resiliently hold the tube 51therewith. This is standard automobile configuration and can incorporatejust gas head or the gas tubes 58 or other gas reservoir without thedivider plate 59 to provide a configuration similar to all presentautomobile shock absorbers. It is preferable that it be used similar toan existing automobile shock absorber but with liquid springcharacteristics on bump to restore the wheel to the pavement faster, asshown in FIG. 7. In accordance with that teach, stroke L denotes wheelreturn from liquid spring stored energy in the liquid chamber on suddenimpact while curve SS with its slower return is the actual curve of astandard coil spring shock response used therewith. This is observedfrom actual tests. Curve L" of FIG. 6 shows the actual stored springenergy, on bump, to accomplish this against the lost (cross hatched)energy of the conventional spring shock. As shown with divider plate 59,the device provides a spring energy stored system in that on impactdivider plate 59 does not permit fluid to go through quite as rapidly asthe rod displacement demands, and temporarily liquid spring pressure isbuilt up in chambers 40a, 40b, which fires the wheel back to thepavement in accordance with the acceleration graph of FIG. 7. We, thus,find that the spring energy is stored to fire the wheel back to thepavement as shown in line L in accordance with my liquid spring patent,instead of the normal spring shock curves SS, with the exception thatsince flow now is between two sides of the dashpot rather than aroundthe tube divider as in the reference patent, plate 59 can be used tocontain gas tubes 58 providing a standard shock absorber for allsituations except high impact when it behaves like a liquid spring.This, then, would provide the high speed wheel return L of FIG. 7 inplace of the slower return SS characteristic of conventional shockabsorbers. The new method of fluid amplified dampening shown hereinpermits this arrangement in a standard shock absorber.

It should also be noted that the configuration of FIG. 1 can be used forautomobile shock absorber purposes and the outer cylinder 52 dispensedwith; in effect, this would provide a device similar to FIG. 1 but in aliquid spring.

In FIG. A it is illustrated that dashpot head 63 having small passages67 added thereto and a plate check valve 68 for closing off reboundpassages 67 on compression and passages 65 on rebound. As noted,passages 67.are smaller because of the smaller rebound displacement ofpiston head 63.

Rebound control can also be obtained by combining the amplifieddampening principles of FIG. 3,3A of my copending patent applicationSer. No. 619,531. It is so intended herein that these combinations arepossible.

FIG. 8 illustrates a straight tubular liquid spring 70 built inaccordance with U.S. Pat. No. 2,909,368 which has the capability ofusing gas in chamber 70a to supplement the liquid spring; liquid beingcontained in chambers 70b, and 700. Chambers 70b and 700 are incommunication through orifice 78 provided in the inwardly formed dashpothead 73. This configuration is similar to the more conventional air-oilshock struts used in aircraft, and the invention covered herein isintended to and will function with these more commonplace structures forshock mitigation.

The invention herein lies in the fluid amplifier dampening associatedwith straight metering stud shock 81 which, in this instance, servesonly as area reduction of orifice 78 and structural support for pistonhead 80a and providing fluid amplifying control flow by providingclearance D. A collector ring 74 and plurality of connecting passages 75function as noted before in FIGS. 2, 3, and 4. Stud 81 has the thread 82and seal 77 to contain liquid of chambers 70b and 700 and separate thegas in 70a. Piston seal 76 acts to contain the liquid in chambers 70cand 70b and guide ring 93 guides the cylinder. Filler plug is used forliquid filling. This system will also work with the stepped tubularspring of Pat. No. 2,809,368 or the metering pin tapered or straight ofany air-oil shock system. In FIG. 9, I taper stud 81a up to shoulders 83and 85 to provide stiffer end loads to illustrate that oldconfigurations can be used with my novel concept of fluid amplofyingshock absorbers. In practice, this step would be slight with fluidamplification to accomplish the same purpose. The stud would, thus, bestronger. It will, thus, be apparent that all existing shock meteringprinciples of tapered pins, notched, deflecting or tapered cylinders,metering tubes, pressure responsive valves or any system, can be usedwith this novel system and an improvement in performance obtained.Actually, with this fluid amplifying principle, the critical tolerancesof all the old system plus one-third the parts and costs are eliminated.

In FIG. 10, I illustrate how the liquid spring assembly 20 of FIG. 1with the substitution of pipe 121 for liquid filler plug 21 and theaddition of liquid port 126' and pipe 127 to cap 125a provides ahydraulic actuating cylinder assembly. Actually, with the addition of anelastomeric seal 128 to head 131, as shown in FIG. 10, I illustrate howthe liquid spring shock assembly 20 of FIG. 1 with the substitution ofpipe 121 of liquid filler plug 21 and the addition of liquid port 126and pipe 127 to cap 125a provides a hydraulic actuating cylinderassembly. Actually with the addition of an elastomeric seal to groove 32of piston 31 of FIG. 1, such a device could be provided. I prefer,however, because of costs, to eliminate passages 3301 FIG. 1 in pistonhead 31 to provide head 31 so that costs are lowered. In practice, heads31 would be produced without passages 33 and inventory maintained inblank units of this type and as orders for shock absorbers were receivedpassage 33 would then be added. We, thus, have one cylinder assemblyadapted to both liquid spring, spring shock, or hydraulic or pneumaticcylinder and costs are thus reduced.

In FIG. 11, I illustrate a cylinder assembly 220 having an elongatedcylinder 222, cap 225, and piston assembly 230. Piston head 230bthereon, which includes shock piston section 231 thereon. Piston head231 has a metering section 232, 233, and 234 in accordance with myprevious teachings herein. In addition, a spaced sealed head 250 isprovided which acts as a sealed hydraulic piston by virtue of seal 251in groove 252. A plurality of passageways 235 are provided communicatingwith bore 236 of piston rod 230a, cap 280, and flexible hydraulic hose270. Cap 280 has an actuating pin eye configuration because of bore 271and is sealed at 272 to provide a sealed cap.

The purpose of this configuration is to provide controlled resistance inan actuator system wherein on compression of the cylinder, controlledflow through fluid amplifying section 232 acts to control velocity andforce. Such a system would work well with gas applied to chamber 222aand liquid in chamber 222b. It is thus intended that my fluid amplifyingsystem work with all hydraulic, pneumatic, or shock absorption or liquidspring systems.

In FIGS. 12 and 13, I illustrate a rotary or oscillating vane-type shockabsorber 150 which is identical to the vane-type shock absorbers used asshimmy dampeners and for shock absorbers on difficult military equipmentwhere a telescoping shock absorber cannot be used. Similarconfigurations are quite often used on hydraulic door closures and wereused on vehicles.

As shown in FIG. 12, a bell crank 153a is affixed to a rotatable shaft153. Bell Crank 153a is generally attached at 1531) to a lever armconnected to the work or the apparatus whose shock must be dampened. Inpractice, bell crank 153a is of sufficient length so that in the normalshock absorber application it will provide approximately a 90 to 120sweep. Because of the novel dampening system we employ herein, it iscontemplated that our shock absorbers will be permitted to sweep achamber of approximately 300, Thus, automatically, our rotary shockabsorber will provide a more efficient energy package for a given size.This is entirely predicated on the use of the fluid amplified dampeningdescribed hereinbefore. The body of the cylinder 170, as shown in FIG.13, has a divider wall 171 extending into the cylinder to its axis. Thisneed be only a 20 angle in the shock absorber in our design; but in mostdesigns using these principles, the divider walls 171 compriseapproximately a 60 sweep of the cylinder which, with the two bladescustomarily used, provides a maximum travel of 120. However, because ofour novel dampening, only one blade 151, attached to shaft 153, isrequired, as will be discussed hereinafter. To utilize the greatertravel now available, a gear could replace bellcrank 153a on shaft 153.Since most of these devices also require pressure responsive valves, theinwardly formed divider wall 171 generally includes pressure responsivevalve with difficult porting and metering. We have herein eliminatedthese valves, the porting and metering, besides accomplishing a 300shock absorbing stroke. Vane 151 has an annular gap 154 which isnormally sealed on most vane-type shock absorbers. This clearance 154provides less critical tolerances. Heretofore, this was a complicatedsealing arrangement and is herein not required. A longitudinal collectorgroove 155 is provided in vane 151. A plurality of passages 156 connectthereto and to chamber 162a. Likewise, in the inwardly formed dividerwall 171, a collector groove 165 and a clearance amplifying orifice 164are employed. A series of passages 166 communicate with collector groove165.

When the vane is accelerated in the direction 161, a sharp corner 1550of collector groove 155 restricts flow therethrough in accordance withan orifice co-efficient of 65 percent. Meanwhile, rotation of hub 153 isaccelerating fluid flow through clearance 164 causing an amplified flowfrom collector groove 165. We thus have a square top energy wavegenerated by movement in this direction. Since the amplified flowvelocity is smaller at the center of the unit, this would generally beused, for instance, to control rebound such as on an auto shockabsorber.

Conversely, to take care of heavy bounce, the vane would move in thedirection 162 into chamber 162a, causing high velocity flow at 154 whichwould amplify flow through collector and passages 156. We, thus, providean amplified shock absorber on bounce which, because of the largediameter sweep of vane 151 at the outer extremity of cylinder chamber170, provides large amplified flow at 154 and 155 for the bounce of thevehicle while the amplified flow at 164 and 165 on rebound is inaccordance with a predetermined return velocity of a wheel from a givenpoint, which velocity is due to the acceleration of the spring only.While I have discussed this in connection with vehicle suspensions, itis obviously suited for may differential velocity situations. Since thevane traverse such a large chamber, this device provides twice theenergy of a conventional vane-type shock absorber. It should be notedthat the flow control orifice and collector groove shown here have alsobeen used on telescoping shock absorbs, such as on FIG. 1 through FIG.11.

Although the unique shock absorber assemblies of this invention arecharacterized by a number of unique properties, it should beparticularly noted that high efficiency shock curves are developed bymeans of entrainment of fluid flowing through the'orifices whichinterconnect the piston head or vane transverse surface and theindentation formed in the peripheral surface of the head or vane. Thisentrainment is caused by the high velocity fluid flowing through thefluid passage clearance between the head or vane and the chamber housingthe head or vane.

It should also be noted that the shock assemblies of this invention canreplace metering pins, metering holes, and pressure responsive valves ofconventional shock absorbers without any appreciable loss of shockabsorption properties.

Moreover, the shock assemblies of this invention permit fluid passingthe piston head or vane (clearance) to accelerate flow through theplurality of orifices to provide a shock resistance in accordance withtapered metering pins, graduated orifices, or pressure responsivevalves, without any of the deficiencies or high cost associated withsuch devices.

In shock absorbers utilizing either metering pins or metering tubes, thetube or area of the metering pin is normally quite substantial as aresult of rigid structural requirements. This structural requirement andconsequent large area, reduces the area for shock mitigation and,therefore, raises operating pressures. The device of this invention,however, operates at low pressures. For example, the shock absorbers ofthis invention, when used on an ingot mold car, have a peak force of120,000 versus 180,000 pounds for conventional shock absorbers and anincrease in energy absorbed from 108,000 inch pounds to 150,000 inchpounds for a stroke of l inches. Accordingly, a car weighing 14,000pounds can be dropped 15 feet, using the shock absorbers of thisinvention versus only 1 1 feet for conventional shock absorbers.

It should be understood that various modifications and changes in theembodiments discussed herein can be made without departing from thespirit and scope of this invention.

I claim:

face adjacent said housing means and a transverse sweeping surface, theimprovement comprising said sweeping means having a first unrestrictedfluid passage clearance between said housing means and said peripheralsurface for fluid therebetween and at least one opening formed in saidsweeping means between the axis of said sweeping means and theperipheral surface thereof, said opening being substantially parallel tosaid first fluid passage clearance and providing a second unrestrictedfluid passage for the flow of fluid, the flow of fluid through saidfirst fluid passage clearance intersecting the flow of fluid throughsaid second fluid passage to accelerate and amplify the flow throughsaid second fluid passage.

2. The shock absorber of claim 1 wherein said housing means is acylinder and said sweeping means is a vane.

3. The shock absorber of claim 1 wherein said second fluid passagecomprises a plurality of orifices formed between the peripheral surfaceof said sweeping means and the axis of said sweeping means.

4. The shock absorber of claim 3 wherein said plurality of orificesprovide a plurality of longitudinal collector grooves for said sweepingmeans.

5. The shock absorber of claim 1 wherein a divider wall is provided forsaid housing means, said divider wall extending from the inner surfaceof said housing means inwardly to the axis of said sweeping means, saiddivider wall further providing a fluid passage clearance between saidsweeping means and said divider wall.

6. The shock absorber of claim 5 wherein said sweeping means is a vanerotatably mounted on a shaft member and said divider wall extendsinwardly from the inner surface of said housing means to the axis ofsaid vane and provides a first fluid passage clearance between saidshaft member and the peripheral surface of said divider wall, saiddivider wall also having at least one opening formed between theperipheral surface of said vane and theinner surface of said housingmeans, said opening being oriented in the same flow direction as saidfirst fluid passage clearance and providing a second fluid passage forthe flow of fluid, whereby the flow of fluid through said first fluidpassage clearance accelerates the flow of fluid through said secondfluid passage.

nNnEn STATES PATENT OWE QERTEFIQATE @F CQRRECTEQN Patent No. 3,698,521Dated Oct. 17, 1972 Inventor(s) Paul H Taylor It is certified that errorappears in the above-identified patent and that said Letters Patent arehereby corrected as shown below:

Column 11, line 9, after "fluid" insert flow.

Signed and sealed this 3rd day of July 1973.

(SEAL) Attest:

EDWARD M.FLETCHER,JR-. Rene Tegtmeyer Attesting Officer ActingCommissioner of Patents FORM PO-105O (1O-69) USCOMM DC 60376.:69 h u 5.GOVERNMENT nmmuc. orncc: usage-sun

1. In a shock absorber having a housing means adapted to hold a body offluid and sweeping means rotatably disposed within said housing means,said sweeping means having a circumferial peripheral surface adjacentsaid housing means and a transverse sweeping surface, the improvementcomprising said sweeping means having a first unrestricted fluid passageclearance between said housing means and said peripheral surface forfluid therebetween and at least one opening formed in said sweepingmeans between the axis of said sweeping means and the peripheral surfacethereof, said opening being substantially parallel to said first fluidpassage clearance and providing a second unrestricted fluid passage forthe flow of fluid, the flow of fluid through said first fluid passageclearance intersecting the flow of fluid through said second fluidpassage to accelerate and amplify the flow through said second fluidpassage.
 2. The shock absorber of claim 1 wherein said housing means isa cylinder and said sweeping means is a vane.
 3. The shock absorber ofclaim 1 wherein said second fluid passage comprises a plurality oforifices formed between the peripheral surface of said sweeping meansand the axis of said sweeping means.
 4. The shock absorber of claim 3wherein said plurality of orifices provide a plurality of longitudinalcollector grooves for said sweeping means.
 5. The shock absorber ofclaim 1 wherein a divider wall is provided for said housing means, saiddivider wall extending from the inner surface of said housing meansinwardly to the axis of said sweeping means, said divider wall furtherproviding a fluid passage clearance between said sweeping means and saiddivider wall.
 6. The shock absorber of claim 5 wherein said sweepingmeans is a vane rotatably mounted on a shaft member and said dividerwall extends inwardly from the inner surface of said housing means tothe axis of said vane and provides a first fluid passage clearancebetween said shaft member and the peripheral surface of said dividerwall, said divider wall also having at least one opening formed betweenthe peripheral surface of said vane and the inner surface of saidhousing means, said opening being oriented in the same flow direction assaid first fluid passage clearance and providing a second fluid passagefor the flow of fluid, whereby the flow of fluid through said firstfluid passage clearance accelerates the flow of fluid through saidsecond fluid passage.